Barovacuummeter.



G. FRBRIGHS.

BAROVAOUUMMETER.

APPLICATION rlfnn Nov. a, 190e.

960,633. Patented June 7,1910.

2 SHEETS-SHEET 2.

rc/Ma i L aowa. y n r Zd@ UNITED STATES GUSTV FRERICHS, OF HANOVER, GERMANY.

BAROVACUUMMETER.

Specification of Letters Patent.

Application tiled November 3. 1908. Serial No. 460.963.

To u/ irioni. it may concern:

Be it'. known that I, GUsTAv Ennemis,-

eivil engineer. a suhject ot the King of Prussia, tierinan Emperor, and residing at .\'o. :i1- Wcdckindstrasse, at Hanover, ir. the

Kingdom of Prussia. German Empire, have l invented a new and Improved lhirovacuiunmeter. ot' which the following is a specification.

rThis invention relates to an apparatus, hy means of which the height of a. partial vacuum existing' in a closed vessel may he given m peri-ents of the atmospheric pressure existing at the time` ot' measuring. The

indication of a vacunmineter depends notonl v upon thc vacuum. hut lipoii the outer pressure also, and to 'attain the correct'. numhet ot' millimeters or of perceuts. a eorrection with respect to the just existing atmospheric pressure must he made. This is gein crally done h v way of calculation, hut it can he done also autoimitically, as is thc case in the present invention.

ln order to make my invention more clear,

I refer `to the accompanyingl drawing, inl

which similar characters denote similar partsl throughout the several views, and in which- Figure 1 is a plan of one form of constriiction of my improved harovaenuinmeter,

l"i;r. is an inverted section in line 2-2 of Fig'. l, Fig. Il is a diagi'aniuiatical repi'efseu- I tation ot' :i part .of Fig. 1 .showing the appaj ratiis eoinhined with au auxiliary vacuummeter scale; Fig'. si is a representation of such a scale, and ["ig. 5 is a diagrainimitimil representation of a section in line :'iof Fig. 3.

'l`he casing i/ is divided hy a partitionj wall n. into a tower compartment ri2 and an upper Y'one 11: the latter is closed h v means of a glass-plate Il'.

as an example a tuhulai' vaeuiunmetei' /f.and

the ouipartnient uf coutaiiis in this forni ol' construction au aneroid-hai'ometer e. 'l'he free end of the vacuum-tithe /i is connected f h v a rod /i with a double-armed lever b2 /is i -supported hy means ot' an axle in hearingalso heid liv said hearing-plates' I' l/"'. rllie i Shaft i' exiteiids through the pai'titioii-\\fall 41.. as well as through a hall-hearing f heid l h v a eolumii f' also lixed to said wall M The couipaitiueiit ff-'f contains, i'n thc form of construction shown tand the free end of the shaft e carries a pointei' or hand c'' rotatinl:r in .front of a dial ,r/ located near the glass-plate (1*. The dial 5'/ has a circular vaeuununeter-scalc if' divided into percents, the length of this scale corresponding normally to a circular bai ronieter-scaie /i provided upon a ring ii attaehed to the casing o in thc plane of the dia'l f/. li`he hand c: serves for the vacuumnieter-scale and a pointer y" attached to the disk ,r/ serves for the barometer-scale.

I prefer to provide, for one apparatus not. only one vacuununeter-scale corresponding to the mean atmospheric pressure of the place where the apparatus is in use, but I provide moreover a certainnuinher of vacuuniuicter-scales. or port-ions ot' such Scales, for other atmospheric pressures such as are known to occur at that place. Suppose, for instance, the mean atmospheric pressure at.

a certain piace he T mui., I provide scales for TG5, 770, 775, 7S() nini., and so on, as well l: as for 755, T50, T45 nim., and so on, it being understood that the ditl'erenee need not by any means he just 5 nini.. hut for instance '4, or 3, or ti, or as other'w'ise. preferred. Normally, the apparatus has the disk with the main scale for the mean atmospheric pressure. ()nl.v when intendingr todetermine the pereents of the vacuum in the closed space with which the tube 7i is connected, that dislewheu the poiiitery* indieatesupoii the laironietcr-scale another' atmospheric pressure, covered with an auxiliary scale, or. more precisely. with a portion of :such a `calc, ty', ["igs. 3 and 4i. This is thus a scale the division of which corresponds hettei' to the atmospheric pressure just indicated liv the pointer i/. Suppose, thc pointer 1/i; indicates 'U34 inni.. the vacuum- ?nieieiseale l'or Tui iuui. will he chosen; or if the pointer y indicates Th2 uuu.. the vaeiiuiumeter-seale for TDH min. will he ichoseu. tl'ovided. the dill'ci'enees hetweeii the vai'iou` scales amount to 5 liiiu. lint, as already stated, this: is no "wom/fio .w'iic '/'e/ moi ll' one ol' the auxiliary vacuf uinnieter--eales must he used. it is introduced into the casiu; r o through a lateral f `lot ff". Fia. and takes them over a portion of the haroineter-seah, as well as over of the disk o. lint while this latter pori tion is covered h v that auxiliary vacuuml meier-scale, so as to l'orni a suhstitute for l the covered portion of the nalin-scale, the

Patented June. 7, 191.0.

a portion ot' the main vacuunimetcr-scale.

respective portion of the barometer-scale remains visible, as does also the pointer y", since the auxiliary vaeuummeter-seaie has a cut-out ol. sullieient size. Now, while the ringr /ly is at any rate stationary, as is also the auxiliary vaeunuuneterscale perhaps employed, the' disk y is eapabbl of a partial rotation. and vthis rotation is brought. about automatieally by the barometer c at every ebange ol' the atmospheric pressure. The disk 5/ is secured to a hollow shaft y* held by the` ball-la-aring f and guided by a erossbar f" and ineiosing the foremost portion of the shaft c'. Une end of a lightl chain l.: is wound around said hollow shaft y/',;|nd the other end is secured to an arm f tixed to a .shaft /I.-`'. This shaft is supported by bearings z' i' and carries also a double-armed lever arranged at right angles to the arm )ne arm of the lever i: has a eounterpoise 2'3 and the other arm is firmly eonneeted with a rod i extending parallelly or nearly so, to the shaft s, The rod z" has at its free end (near to the bearing an extension if* arranged at right angles` to said rod and being thus` parallel to the artn ltr. 'l'he free end of said extension is eonnected with one end of a bar ni fixed at its other end toa broad, U-shaped spring m by means of a connecting-pietre mf". )ne leg of this spring is secured to a rigid stationarv Support 11,. the other is attached to a column e' fixed to the undulated top-plate of the barometer n.

Suppose, the atmospheric pressure. inereases, the top-plate of the barometer is depressed eorrespomling to that increase nml this motion is transmitted to the bar m/ by the mediation ot' the spring 1u. The bar m' is thus also depressed, 1'. e. moved in the direetion toward the partition-wall u', as are also the rods F' and i. Owing to this movement, the lever i: and the arm are turned and thus the chain is eaused to rotate the hollow shaft r/, the direction of this rotation being sueh that the ditl'erenee between the indieation of the hand c'' upon the seale g2 and the absolutely eorreet indieation that exaetlSy eorresponds to the just existing*atmospherie pressure is reduced, that is to say, is praetieally nearly eoinpletely eompensated.

In Fig. l, the vaeutmnneter-seale eorresponds to Ttt) millimeters, and there is no compensation neet-ssa ry and does not or eaunot take place so long as the atmospherie )ressure amounts exaetly to Tti() millin'teters. l3nt to obtain alwaysl an exaet staten'tent of the bereents of the. vaemuu. the v:u:uunnneter seale should always exaetly eorrespond to the atmospherie pressure just existing. To obtain this itl a praetieallt' sullieient degree, l have provided auxiliary seules y', ot whieh one is shown in Fig. t. 'lhis is sueh an auxiliary seale. as bas already been inenl l l y l l l l l l l l tioned in a foregoing portion of this Specilieation, and it. is that. scale eorresponding to an atmospheric pressure of Tl() millimeters. Now, suppose the pointer y of the dislt y indieates T10 millimeters, the eorresponding auxiliary .st-ale is introduced through a slot tr" (Fig. :2) into the easing a where it is heldby -t'rirtion between and by angular pieees o o (Fig. Il). 'lhe scale y has a eut-out y* (Fig. l) through whirh the otherwise covered portion ol' the barometerscale remains visible, and the seale proper gi' of the auxiliary scale y is so divided that the numeral 1(10 (pereents) is just. opposite to the numeral T-l trentina-ters) ot the barometer-Scale l1'. 'libe indieatiou ofthe hand e`` as to the pereents of the vat-num is then absolutely eorreet. and the same is true with respeet to every other auxiliary seale proporly chosen. Suppose.l the barometer indi- Cates an atmospheriel pressure of say T68 or T72 millimeters, the auxiliary vaetuunmettaseale for TTU miliimeters will be ehosen as that nearest to those prt-saires aml thus best fitting for the same. The. band on stands in .sueh a ease at or over TGS or TT. millimeters. as the ease may be, and the hand e indieatesl upon that auxiliary vaeuununeterseale the number of the pereentsl eorrespontb ing to that atmospherie pressure, either exactly or very nearly so.

Ilaving now deseribed my invention. what I elaim as new, and desire to seeure by Letters Patent. isn* 1. The combination with a \':uu|uumeter. of a barometer, means adapted to eanse the barometer to eompeusate the. intlueuee of ehanges` of the atmospherie pressure upon the iudieation ol the vaeuumnn-lel'. and a plurality ot' interehangeable \:u'uum|neter Seules eaeh '.orrespondin;r to a distinet atmospheric. pressure, and heilig eaeh 'adapted to be altar-hed to said vzwuummeter, for the purpose deseribed.

Q. The eombination with a vaeuummeter having a scale corresponding to a distinet atmospheric pre sure, of a lmrometer, means adapted to eause the baronn-ter to eompensate the intluenee of ehauges of the atmospherie. pressure umn the indication of the vaeuummeter, antl a plurality ot' auxiliary interelutngeable vaeuunnneter-srales having their seales correspond to other distinet atmospheric pressures and being eaeh adapted to be attached to said vaeuuuuneler so as to be able to eoiiperate with the band of the same, for the pur )ose as described.

In testimony tiat l elaim the foregoing as my invention, l have .signed my name in preseuee of two .subseribing witnesses.

(lSTAV Flll'lllltfllh'.

i i't nesses i li. llottxonrnxtz, ll. ll.\.\st:.

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